Setting the memory speed right (?)

Hi all.

I have a new memory that I want to set it right and I can't seem to understand the Gigabyte x38-ds4 bios.

This is what I have: OCZ Titanium PC2-9600 2X2GB @ 2.15v



and the BIOS (not my settings):

I don't understand this MCH strapping.

My mem can work at 1150MHZ but even at 1111MHZ it is not stable. I managed to play and work with the computer but today the OS didn't load and I guess it's because of the mem. So I messed up with this MCH thing to get 3.33C which gives me 1066MHZ which is also fine by me but I don't believe that my system is stable...

How should I set the speed correctly?

I have C1E and EIST enabled.

9 answers Last reply
More about setting memory speed
  1. That's an awful tall FSB, you may just be running into an 'FSB wall' - what CPU are you using? Is the RAM 2x2, or 4x1 (which has it's own set of fixes)?

    "(G)MCH Frequency Latch" which we mostly refer to as a 'strap' are sets of northbridge timings - much like memory latencies, the faster you go, the 'looser' the timings have to be... There are four straps, corresponding to the Intel FSB ratings: 200 (800FSB), 266 (1066FSB), 333 (1333FSB), and 400 (1600FSB - Intel actually does make a 1600 FSB CPU - the QX9775 - but, I think, it's over $1500 a pop!); each strap has it's own set of available memory multipliers (ratios). The strap latencies, for some northbridges, don't 'kick in' until one over the selected strap; so, in other words, setting the clock to 401 guarantees that you're getting the 400 latencies/timings... At that high an FSB, you definitely want the 400, or 'D' memory multipliers, which means you're limited to 2.0 (1:1), 2.66 (4:3), and 3.33 (5:3)...

    I have C1E and EIST enabled.

    Those are a problem when overclocking; you can either OC, or run the 'green' stuff at stock speeds, but you generally can't 'have your cake and eat it, too!'

    I recommend the following for any OCd system:

    On the "Advanced BIOS Features" page:

    "CPU Enhanced Halt (C1E)" to "Disabled"
    "C2/C2E State Support" to "Disabled"
    "C4/C4E State Support" to "Disabled"
    "CPU Thermal Monitor 2 (TM2)" to "Enabled"
    "CPU EIST Function" to "Disabled"

    On the "MB Intelligent Tweaker(M.I.T.)" page:

    "Robust Graphics Booster" to "Auto"

    ******** Clock Chip Control ********
    >>>>> Standard Clock Control

    "PCI Express Frequency (Mhz)" to "100" (not auto...)
    "C.I.A.2" to "Disabled"

    ******** DRAM Performance Control ********

    "Performance Enhance" to "Standard"
  2. My CPU is intel E8500 not OC.

    The FSB is 333MHZ

    I use 2X2GB sticks.
  3. I'm sorry - I missed the "(not my settings)" caveat...

    Have you tried the "Load Optimized Defaults" function in the BIOS - it runs a chunk of 'discovery' coade that properly sets all the myriad 'auto' parameters in the CMOS...
  4. I haven't but I'll try. the issue for me is having my memory running at the speed it should, e.g., 1150 or OC it to 1200
  5. You can always use faster RAM with any modern CPU/MOBO setup - you're just likely to have to set it up manually in the BIOS to take advantage of it. Pretty much all DDR2 ram is actually DDR2/800; they 'speed-bin' it, i.e., test and select the sticks that will work at either lower (faster) latencies, or higher (faster) speeds, or both, and sell it at a premium as 2/1066, 2/1200, and so on. JEDEC spec'd RAM has a little EEPROM chip in it that stores the set-up information/tables for running it at 800 at various FSB (Front System Bus) speeds - has the preferred memory multiplier and timing info - this is called an SPD (Serial Presence Detect) just to confuse us; faster, higher rated sticks may (but don't necessarily) contain another set of tables (called an EPP - this one makes sense - Extended Performance Profile) that will tell the BIOS what multiplier/latncies to use at its higher rated speed - BUT - not all BIOS are created equal: some will read this EPP automatically, and set the RAM at the higher speed; some will require intervention (on a lot of GBs, it's "Load Optimized Defaults" [but, to keep it more confusing - not all BIOS with the "Load Optimized Defaults" fuction actually use it to set the EPP]), and some just plainly don't know the EPP exists (if it does) and you have to set the higher speed manually!

    You have control over the basic system clock (I'm going to cal it B_CLK), once you start manually timing the MOBO through the BIOS. B_CLK times four is your FSB (once again, Front System Bus); B_CLK times your memory multiplier is your DRAM rate; B_CLK times your CPU's multiplier is your CPU frequency.

    Examples: if you set your system clock to 333, you will need a 2.4 memory multiplier (333 x 2.4 = 799.blahblahblah) to run your RAM at 800, and if the CPU multiplier is, say, 8.5, you will get a CPU clock of 2.83GHz; at that same B_CLK you would need a memory multiplier of 3.2 (3.2 x 333 = 1065.6) to take advantage of 1066 RAM. Now, lots of CPUs that are rated at a 1333 nominal FSB will run a lot faster, sometimes with a little more 'oomph' from a voltage increase; for example, I run a Q9550 that is rated at 1333 FSB (333 B_CLK) times an eight point five multiplier, for a 2.83GHz speed. It will comfortably run with the B_CLK well over 450 - and here's where faster RAM comes in. The smallest RAM multiplier available from a MCH (Memory Control Hub - or 'NorthBridge') is 2.0, but, with a 2.0 multiplier, that means at a 450 clock, your RAM will need to run at 900 (again, 450 B_CLK x 2 = 900), which most 800 RAM just won't do! This is referred to as a 'RAM limited bus', meaning the CPU can't run a B_CLK any higher than (roughly) half the RAM's available speed - and thus, the need for faster RAM. Mind you, this only applies if you both can, and intend to, run your FSB above 1600 (once again, a B_CLK of 400+ times 4 gives you a 1600+ FSB)... Be aware, too, that the memory multipliers are not the decimal numbers shown in the BIOS - they are integer ratios, so you can't just 'plop in' any decimal mult you please - you are limited to using the existing set!

    To further complicate matters, people often misunderstand the actual quantitative speed improvements inherent in faster ram... Here's the mistake: 1066 is 33% higher than 800 ([1066-800]/800 = 266/800 = .33), so 1066 RAM must be a third faster than 800, right? Not so! You have to figure in latencies. Most 800 will run at 4-4-4-12, while most 1066 is rated at 5-5-5-15, or, even worse, 5-5-5-18. Here's how to appraise the situation in reality: at 800 MHz, a RAM bus cycle is 1.25 nSec long (1000/800); at 1066 (1000/1066), it is roughly .938 nSec long - so, with an 800 stick at a 4 average latency, a RAM bus transaction takes 1.25 (cycle time) times 4 (latency), or 5nSec, while at 1066 it is .938 (cycle time) times 5 (latency), for a transaction time of (roughly) 4.7nSec - so you see, by going to nominally 33% faster RAM, you actually gain three tenths of a nSec per transaction - .3 (transaction gain) over 5(transaction total) = .06, for a real-world improvement of 6%

    You have an oddball speed there; there's no easy answer. If you leave your processor at the stock 1333 FSB (333 sytem clock) you have these choices:
    3.20 multiplier (8:5 ratio on the 333 ['B'] strap): 333 x 3.20 = 1066
    3.33 multiplier (5:3 ratio on the 400 ['D'] strap): 333 x 3.33 = 1109
    4.00 multiplier (2:1 ratio on the 333 ['B'] strap): 333 x 4.00 = 1332 (way too high!)
    If you raise the FSB to the next 'notch', 1600 (400 system clock), the situation gets no better:
    2.40 multiplier (6:5 ratio on the 333 ['B'] strap): 400 x 2.40 = 960
    2.66 multiplier (4:3 ratio on the 400 ['D'] strap): 400 x 2.66 = 1064
    3.20 multiplier (8:5 ratio on the 333 ['B'] strap): 400 x 3.20 = 1280 (again, likely too high...)

    So you see, the point of having fast RAM is to get 'headroom' for overclocking your CPU, not to hit the RAM's top speed right on the nose. Here's a little chart showing the process of 'walking up' the CPU frequency 'through' memory bandwidth provided by differing multipliers:

    If you'd like (and have any cooling other than the stock Intel HSF) I could work you up a 'quick and easy' overclock, that wouldn't push the voltages or the hardware anywhere near affecting long term equipment survival... Those 8500s are mighty overclockers - I think we can hit 3.8GHz with no muss or fuss!
  6. That's a handy dandy little chart you got there bilbat. Do you mind if I save it somewere?
  7. Ok I managed to do a bit of OCing and here are the details:

    I changed the:
    Multiplier to: 9.0 (instead of 9.5)
    Bus Speed: 360 (instead of 333)
    I got rated FSB: 1440MHz
    CPU: 3.24GHz (instead of 3.16)
    CPU Vcore: 1.33 volts
    CPU temp: 34~38 deg.
    Core temp:52deg. (max 69 at load).

    DRAM: 1152MHz (instead of 1066MHz) Don't forget that this memory is manufactured for 1150MHz and I'm sure I can OC it to 1200Mhz.
    FSB : DRAM: 5:8
    CAS/RAS: 5 5 5 18

    So far the system is stable but I didn't use benchmarking software nor games to verify stability. But I did noticed that the Windows Performance Assessment got my higher scores. I run a dual boot of Vista 64 and Windows 7 (64bit).
    The highest improvement was in graphic and gaming graphic according to Windows 7.
    I got from 6.5 to 7.5, I use ATI Palit 4870 1GB dual edition.

    I don't know if I did right and I sure would like some more advice.

    Thanks :)
  8. These would be my recommendations; again, it won't run your memory at its rated speed, but the machine will speed up enough so you won't obsess about it!

    A lot of this is 'canned' - so if you've seen parts of it before, skip ahead!

    Gigabyte GA-EX35-DS4
    Intel E8500 sSpec SLAPK 1333FSB x9.5mult 3.16GHz .85-1.3625V
    OCZ PC2-9200 Titanium 4GB (2 x 2GB) 240-Pin DDR2 SDRAM 1150 memory: 5-5-5-18-2t nominal 2.2v

    If you haven't yet done it, put in one stick, start with a BIOS' "Load Optimized Defaults"

    Before we start ramping things up, I want to teach you a new skill involving the BIOS: Do the <DEL> at the boot to enter the BIOS; notice, at the bottom, the <F11> "Save CMOS to BIOS" - hit this, and you should get a menu that will show a number (the count varies by BIOS) of empty 'slots', each of which will store an entire set of BIOS parameters, to be re-loaded from the corresponding <F12> "Load CMOS from BIOS"; this is a wonderful overclocker's feature. What I do with it, is to save my 'baseline' working parameters, so if I change something that 'irritates' the board, and forces a reset of all the parameters to defaults, or, even worse, get so screwed up I need to do a 'clear CMOS', I can get back to my starting point with no effort, and without having to remember 85 separate settings! Another thing it prevents is two hours' troubleshooting, having forgotten a change to a crucial parameter - like, "wait a minute - didn't I have the Trd at seven?!" It's pretty self-explanatory, and I alway urge people to start right away by taking the time to give the 'slots' names that mean something: in two hours, "Try2" and "Try3" will not be very helpful, but "450@+10MCH" and "450@+15MCH" will! Another use is for 'green' settings; overclocks, as a rule, do not 'play well' with green features, such as 'down-clocking' and 'down-volting'; with the storage slots, you can set up one profile, say "Green", with all the settings at 'stock' values, and all the 'green' features
    enabled; another, say "Balls2Wall" with a full overclock, and all the 'green' stuff turned off... Another neat feature of this 'slot' system is, for most BIOS, the mechanism itself will keep track of which ones have booted successfully, and how many times (up to, I believe, a max of five)!

    On the "Advanced BIOS Features" page:

    "CPU Enhanced Halt (C1E)" to "Disabled"
    "CPU Thermal Monitor 2 (TM2)" to "Enabled"
    "CPU EIST Function" to "Disabled"
    "Virtualization Technology" to "Enabled" - this allows use of Win7's fantastic VirtualXp feature...
    "Full Screen LOGO Show" to "Disabled"

    On the "Integrated Peripherals" page:

    Your manual shows "Legacy USB storage detect", but later BIOS say "USB Storage Function" - either way, set to "Disabled"

    On the "Power Management Setup" page:

    "ACPI Suspend Type" to "S1(POS)" (for now...)
    "HPET Support" to "Enabled"
    "HPET Mode" to whichever OS type you're running - "32-bit" if an x86 version, "64-bit" if an x64 version...

    On the "MB Intelligent Tweaker(M.I.T.)" page:

    "Robust Graphics Booster" to "Auto"
    "CPU Clock Ratio" to "9"
    "Fine CPU Clock Ratio" to ".5"
    "CPU Frequency" - this one can't be set, it's calculated, and will change when we set the next few items...
    "CPU Host Clock Control" to "Enabled"
    "CPU Host Frequency (Mhz)" to "401"
    "PCI Express Frequency (Mhz)" to "100" (not auto...)
    "C.I.A.2" to "Disabled"
    "Performance Enhance" to "Standard"
    "System Memory Multiplier (SPD)" to "2.66D"

    The strap latencies, for some northbridges, don't 'kick in' until one over the selected strap; so, in other words, setting the clock to 401 guarantees that we're getting the 400 latencies/timings...

    "Memory Frequency (Mhz)" - again, can't be set, it's calculated...
    "DRAM Timing Selectable (SPD)" to "Auto"
    You should be able to leave the rest of the memory settings alone; we haven't changed its actual speed, so it should keep working...

    "Load-Line Calibration" to "Disabled" (this works differently on different boards - on mine, it's worse "enabled" than "disabled" - the function is

    supposed to cure a phenomenon called Vdroop - the CPU voltage regulation circuit causes the CPU core voltage to sag, or 'droop' under high loadings;

    hopefullt, we're going to be at a low enough voltage to just ignore this...)
    "CPU Vcore" to "1.3250V"
    & "MCH Core" to 1.200V" if you intend to add more than two sticks of ram...

    And that should do it!

    I should point out that getting two reboots in a row here is perfectly normal behavior; it seems that, when you change certain settings (and we don't exactly know which ones - the only sure one I know is Trd - if you change it, I think you get the 'twin' reboot) it boots once to 'see where it's at', recalculates its remaining 'auto' settings, saves them, and then boots again. Three reboots in a row, however, usually indicates that the board was 'given indigestion' by your settings, and is going back to defaults. This sometimes goes astray, and it doesn't get back into proper operation - for example, at this point, mine will sometimes 'lock' itself into 111MHz x a six multiplier - and take a week to do a whole boot - that's time to do a CMOS reset, and use your 'stored' <F12> profile to get back to where you were...

    Good luck!

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